n  = eval(input("请输入数量: "))
if n==1:
    cost = n*150
elif n>=2 and n<=3:
    cost = n*150*0.9
elif n>=4 and n<=9:
    cost = n*150*0.8
elif n>=10:
    cost = n*150*0.7
print("总额为：",int(cost))
